Improvement in fire-alarm-telegraph repeaters



C. H. POND.

FIRE-ALARM TELEGRAPH REPEATERS.

No.188,18.1. Patented March 6,1877.

git 14%.

C. D m T G N u s A W n w R a. 0 N T M m 0 H P Qw R m P N UNITED STATESPATENT QFFIGE.

CHESTER H. POND, OF JACKSON, MICHIGAN, ASSIGNOR TO THE MICHIGAN FIREALARM COMPANY, OF SAME PLACE.

IMPROVEMENT IN FlRE-ALARM-TELEGRAPH REPEATERS.

Specification forming part of Letters Patent No. 188, 181, dated March6, 1877; application filed February 19, 1877.

To all whom it may concern Be it known that I, OHEsTEE H. POND, ofJackson, in the county of Jackson and State of Michigan, have inventedan Improvement in Repeaters for Fire -Alarm Telegraphs, of which thefollowing is a specification:

The nature of my invention relates to an improvement in devices fortransmitting or repeating the signals made upon, or caused by, theopening and closing of the electric circuit in a given loop or districtto the other loop or loops in the fire-alarm system, so that if thecircuit be broken in one loop it will be broken in the others, and willremain so until it is again closed in said loop.

If, from accident or design, the circuit should remain permanentlybroken in one circuit-loop, it is necessary to provide means for closingthe otherloops; otherwise the entire system would be disabled.Heretofore this has been accomplished by mechanical means, which wouldact in closing the loops after they remained open a given length oftime.

The object I have in view is to provide each 'magnet in the repeaterwith a devicewhich will automatically close the circuit of an oppositeloop directly after it has been broken; and to this end it consists,mainly, in a tilting mercury-tube, actuated by the armature, incombination with the connections to the loops and magnets, as more fullyhereinafter set forth.

Figure 1 is a perspective view of a two-circuit repeater. Fig. 2 is alongitudinal vertical section through a mercury-tube at w m, tilted backas when the circuit through the magnet to whose armature it is connectedis broken. Fig. 3 is a similar section, showing the position of the tubewhen the circuit is completed through the said magnet. Fig. 4 is acrosssection at y y.

In the drawing, A A representtwo electromagnets, placed side by sideupon a suitable base, provided with bin ding-postsp,with which the wiresE E and W W of an eastern and a western loop are connected, as shown. BB are the armatures of the magnets, in front of which are respectivelyhung the cylinders G C, of hard rubber, between posts D D, through whichtrunnion-screws a are tapped to pass into sockets in a cradle, b, whichsupports each tube at the center, andwhose ends extend above thetrunnions a. To these ends a fork, d, pendent from a rod, d, is pivotedby screws 0 c, as seen in Fig. 4. The front end of the rod d is pivotedto the upper end of the armature-lever, of which f is the spring,attached by a cord to the adjusting-screw 9.

When the circuit is broken, the armaturespring, in retracting thearmature lever, through the connections above described, tilts back thetube, as seen in Fig. 2; but when the circuit is completed the tube istilted forward, as seen in Fig. 3.

Near the base of each tube an iron screw, 'i, is tapped into it fromeach side, and before the tube is scaled up at the end nearest themagnet a small quantity of quicksilver (represented at h) is introduced,so that if the tube be tilted back the points of the screws 0' i wouldbe submerged, and an electric current might be passed from one screw tothe other.

Between the spools of the several magnets binding-posts F F are erected,each having a contact-point, k, opposing a corresponding point, 70, onthe face side of the armature-lever.

The connections in this repeater are made as follows: From the post p,to which the mainline wire E is attached, a wire, 1, is run to themagnet A; thence, by a wire, 2, to the post F between the helices of themagnet A; thence,

by a wire, 3, to the base-screw i of the tube 0; then another wire, 4,connects the other screw 1; of said tube C to the post p, to which themain wire E is connected. When the circuit in the magnet A is broken,the electric current will pass through the mercury in the tube C, (thentilted back,) and thus complete the circuit through the line E E. Wires5 and 5 connect the base-screws i of the tubes 0 C, respectively, withthe armaturecenters of the magnets A and A. By means of the wires 1, 2,3, and 4, corresponding connections are made with the main-line wires WW of the other loop.

When the circuits are uninterrupted, the electric current passes fromthe line E, through wire 1, into and through magnet A; thence, throughwire 2, to post F; thence, through the points is k and wires 5' and 4,back into main line E. The current through the circuit W W passes, inlike manner, through the corresponding opposite connections.

It follows, then,that when the circuit in both loops is normallycomplete the current must pass through the points k k of each armature.Hence, if the circuit be broken in the line E E, the magnet A will bedischarged, its armature will fall back, thereby breaking the circuit ofloop W W through the points k k of said magnet. The circuit of line W Wremains broken until the mercury-tube O, in tilting back, has submergedits screws 5 i, which recomplete the circuit through the line W W,

in the manner first above described. The operation of breaking andclosing the circuit in the opposite loop is the same.

What I claim as my invention is- In a fire-alarm-telegraph repeater,substantially as described, the tilting mercury-tubes C O, actuated bythe armatures of the magnets A A, for repeating or transmitting thesignals from one circuit to another through the connections,substantially as described.

CHESTER H. POND. Witnesses:

H. F. EBERTS, H. S. SPRAG-UE.

